NSW Threatened Species Scientific Committee Conservation Assessment of Keyacris scurra (Rehn 1952) Key’s Matchstick Grasshopper (Morabidae) B Hope, B Law Version 1, May 2019 NSW Threatened Species Scientific Committee Keyacris scurra (Rehn 1952) (family Morabidae), Key’s Matchstick Grasshopper Photo: Michael Kearney Distribution: Endemic to NSW/ ACT/ VIC (possibly extinct in VIC) Current EPBC Act Status: Not listed Current NSW TSC Act Status: Not listed Proposed listing on NSW BC Act and EPBC Act: Endangered Summary of Conservation Assessment Keyacris scurra Key’s Matchstick Grasshopper was found to be eligible for listing as Endangered B2ab(ii,iii,iv,v)c(iv). This species is endemic to NSW, the ACT and Victoria (although possibly now extinct in Victoria, Vic SAC 2018). The main reasons for this species being eligible are i) inferred restricted geographical range (AOO = 68 km2), ii) severe fragmentation, iii) historical and inferred ongoing decline in abundance, habitat availability and quality and iv) ongoing threats (and poorly understood management requirements). This species was the focus of early chromosomal research (see Grodwohl 2017 for a summary) and unlike many insects, there was extensive survey work performed in the past that allows an historical assessment of the species’ decline. At present only limited recent survey work has been performed, but this limited information indicates this species is now locally extinct at many known locations, indicative of decline. Description and Taxonomy Keyacris scurra (Rehn 1952) Key’s Matchstick Grasshopper is a small (females ~25 mm, males ~18mm), slender, wingless grasshopper characterised by its slanted face, splayed hind femora and ensiform antennae. This species occurs in several colour forms, with brown being the most common (Farrow 2018). A full description is found in Rehn (1952) and Rentz (1991) also has information on this species. Within this species there are two parapatric chromosome races (15 chromosome and 17 chromosome), which are not distinguishable by external features (Key 1987). A similar-looking species which occurs in the same area are nymphs of Acrida conica (Giant Green Slantface), although A. conica develops wing buds which allow differentiation from K. scurra (R. Farrow in. litt. 15 Sept 2018). Keyacris scurra was originally described as Moraba scurra Rehn and was later transferred to the genus Keyacris Rehn (Key 1965). Keyacris scurra is in the subfamily Morabinae (Australian Faunal Directory 2018). The Morabinae is endemic to Australia and includes ~41 genera of flightless grasshoppers grouped into five tribes; many species are undescribed. Keyacris is in the tribe Keyacridini (Key 1976; Australian Faunal Directory 2018).. NSW Threatened Species Scientific Committee Distribution and Abundance Historical distribution Keyacris scurra Key’s Matchstick grasshopper was originally distributed from Victoria (Vic.) to Orange (NSW) across the wheat/sheep belt (White 1956, 1957, 1963; Rowell and Crawford 1995, 1999). This species is typically recorded in native grasslands in the following land-uses: cemeteries, along railway easements, travelling stock routes and more recently conservation reserves in the ACT. Disturbance appears to be an important determinant of site occupancy and it appears to be absent from sites that are disturbed during inappropriate times of the year (and interrupt the short non-overlapping lifecycle) or have been subjected to erratic management (e.g. periods of over and under grazing). More recently this species has been incidentally recorded within a wider range of habitats (R. Farrow in litt. 27 July 2018) than were previously thought to be suitable and further research is required to determine the importance of these locations to the distribution and conservation status of this species. It is also possible that given these newer records are in atypical habitats they may represent a similar but undescribed taxon. Another similar species, K. marcida, occurs to the west of K. scurra and is apparently parapatric. At three places in NSW thesethese species (K. scurra and the related K. marcida) occur within 14-16 km of each other (Key 1981). Specimens The Australian National Insect Collection (ANIC 2018) includes preserved (dry) specimens from most sites in historical surveys (White 1956, 1957, 1963) and the most recent specimen is from 1986 and the collection was accessed on 27 July 2018. Some locations noted in the ANIC collection are outside the distribution documented by White (1956, 1957, 1963). After 1986, ANIC has received an unknown number of specimens which are held in a wet collection, however this collection is yet to be catalogued and was not available for this review. 1950-1990 records This species was recorded at approximately seventy-five sites in the 1950s and 1960s (for maps and lists see White 1956, 1957, 1963; Blackith and Blackith 1969; Rowell and Crawford 1995; 1999). Due to vague location descriptions the total number of known sites is uncertain, however at least 140 2x2 kilometre AOO squares appear to have been occupied in the 1950s, which is indicative of at least 140 populations. This estimate includesincludes records from the 1990-2000s (Rowell and Crawford 1995, 1999) and from 2008- 2018 (detailed below) which are assumed to have also been presenting earlier decades? 1990-2000s records Between the 1970s and 1990s there is a lack of records and published research on this species. In the mid- 1990s surveys for this species were undertaken in the ACT (Rowell and Crawford 1995,1999). These surveys revealed three new sites, with the species confirmed to occur on seven known sites in the ACT. The species could not be located (and therefore may be locally extinct) at two known sites. Rowell and Crawford (1999) stated that by 1999 the species had also disappeared from 'Greenhills' Oval, Brindabella Road, Tidbinbilla Station and Condor Camp (paratype location). Of the seven confirmed ACT sites, five were on conservation reserves (Rowell and Crawford 1995). While it is possible for this species to evade detection during a single survey event (Rowell and Crawford 1999), lack of detection may indicate localised extinction or a very small population (which ultimately leads to a genetic bottleneck and reduced population viability). Butz (2004) reported this species as absent at Blundells Flat (ACT). Pullen (2000) listed the following occupied locations in the ACT: along the railway easement between 'Tralee' and Williamsdale [this is most likely the “Royalla” site studied extensively in the 1950’s]; Captains Flat cemetery; on the lower slopes of Mount Jerrabomberra; and on the southern slopes of, Tuggeranong Hill in the Canberra suburb of Conder. Both Mount Jerrabomberra and Tuggeranong Hill are threatened by housing developments and the Mount Jerrabomberra population’s habitat had apparently already been at least partly cleared in 2000 (Pullen 2000). Very little information is currently available about this species in NSW, although Jones (1993) who surveyed sites in the ACT and NSW (Southern Highlands), did not detect this species in NSW. Credible Bionet records of this species include sites within NSW on the Monaro Plain (e.g. Bredbo Cemetery (1997), Yaouk (2000) and Adaminaby (1997)), which is an area that this species was not reported from by White and other researchers, although the habitat is suitable and contiguous with other known sites. NSW Threatened Species Scientific Committee Contemporary distribution There are recent (2008-2018) credible records from seventeen (AOO = 68 km2) well-dispersed, 2 km x 2 km AOO grid squares in NSW (nine, 2 km x 2 km grid squares) and ACT (eight, 2 km x 2 km grid squares). One major constraint in estimating AOO is that a number of the known locations (e.g. documented in White 1956, 1957) lack detailed descriptions, were mapped at coarse scale and were not able to be relocated by Rowell and Crawford (1995). A survey in September 2017 of twelve of White's (1956) listed sites located two single specimens at two nearby sites (Gundagai and Gundagai South Cemetery) and it was no longer found at sites which were previously studied intensively (e.g. Murrumbateman) (Hoffman and Kearney 2018). Hall Cemetery was surveyed in early 2019 and Keyacris scurra was present (Kearney in litt. Feb 2019). Changes in the management of cemeteries (e.g. mowing) may have contributed to the possible extinction in Victoria (Vic SAC 2018) and some NSW sites. Databases list recent records for a further three sites on (at least in part) conservation reserves in NSW and there are recent records from the ACT attributed to this species at Kambah, Tuggeranong Hills and Mulligans Flat (ALA Accessed March 2018). Kambah (ACT) and Mulligans Flat (ACT) were sites where Rowell and Crawford (1995) detected this species so these incidental records are likely to have been correctly identified. Tuggeranong Hills (ACT) is listed as a known site in Pullen (2000), which again adds credibility to this sighting. Mulvaney (2012) noted the presence of this species in the ACT at Gungahlin (National Transmission Authority land at Crace, Mulligans Flat NR and Crace NR), Hall cemetery (confirmed as present in 2019, Kearney in litt. Feb 2019) and possibly at the base of One Tree Hill (Kinlyside, at Moncrieff and to the north of Bonner). Recent credible photographic records (R. Farrow in litt. July 2018) at three known sites and at seven additional sites (in habitat previously thought to be unsuitable) raise the possibility that this species has a wider distribution than current information indicates. Conversely, while White (1963) recorded this species at four Victorian sites (Merton, Benalla, Beechworth and Wodonga) and there are ANIC specimens in the general vicinity of Bright, Corryong, Omeo and Hinnommunjie, there are no recent Victorian records and the species is possibly extinct in Victoria (Vic SAC 2018). Ecology Keyacris scurra Key’s Matchstick Grasshopper is usually found in native grasslands but it has also been recorded in other vegetation associations containing a native grass understory (especially kangaroo grass Themeda triandra) and known food plants (particularly Asteraceae).